Exploring Fabrication of SS Conical Fermenter: Brisbane Only

[Zorco]

Following a prompt in the Ebay thread, I spoke to a stainless steel fabricator, Harry, near my home about conical fermenters.

Harry has worked on huge brewery plant for Coopers, Brew in Brisbane and others.

What he wants is for us to come up with some concept diagrams. This primitive starting point is important because he is able to call upon standard parts used in industry to reduce cost depending on what we want.

I'm not sure what volume I'd be keen to explore, how simple we would want it etc etc.

And I'm probably doing this on behalf of the Brisbane community who might be interested.

Let's see how it goes, but we could maybe come up with a simple specification, Google Sketchup model and start the chat with Harry.

I don't think showing him a picture of a fancy one and comparing cost is a good plan.

Things to consider off the top of my head:
- Aspect ratio
- total volume
- number of ports
- type of cleaning access

This may not go far, or it might. But we have a skilled tradesperson and I'd like to explore. Jump in if you want to add constructively to the process.

 

[Feldon]

My 2 cents...

You raise a good point about volume size. Should it be single batch size, double or triple?

What no maker has come up with yet is a conical fermentor based on a modular concept instead of a single piece of fabricated metal of a fixed volume.

A modular system would comprise a conical base unit flanged on its upper rim to accept a large tri clamp fitting, and a lid unit (domed?) similarly flanged on its lower rim. Inbetween these two units would be a cylindrical central unit of, say, 20 litres volume, or big enough to brew a single batch when you add in the volume of the cone and the lid units.

To ferment a double batch, just add in an extra central unit, and add another again for triple batches.

The units would be held together by those over-size, multi-hinged tri clamp ferrules (can’t find a pic online right now, but this will give the idea).


I think these modular units might be less costly to fabricate than a regular ‘one-piece’ conicals because there would be easier access to the internal surfaces for welding of ports and fittings etc. They would also be unique on the market (as far as I know) for Harry to perhaps make a killing.

(And taking the modular concept further, there is no reason I can see why the concept couldn’t be extended to mashing by designing a different base unit that included a perforated screen).

Another feature that would be good (whatever you decide to go with) would be a flat surface about 50mm wide running vertically down the side of the vessel. This would be a place for users to drill holes for weldless fittings (eg. thermowells) and the flat surface would assist leak-proof attachment.

Good luck with the project.

 

[Zorco]

Cool approach. Thanks Feldon. And excellent idea about the end user port drilling panel. He has a huge press in the shop and making those creases before the seam weld could work.

And holy crap, more of these ideas please. No one to criticise or dismiss an idea at this stage of brainstorming.

Critical judgement to come.

 

[huez]

Feldon is on a winning design there i reckon, but the costs in having a custom tri clover fitting made that big would be epic for small batch work.

I'd be interested to see where this goes but i can't see it being financially feasible to manufacture something like a stainless conical fermenter in australia. The labour cost alone in just the welding and finishing would be more than most aussie home brewers would be willing to pay for the finished product.

 

[fdsaasdf]

Thanks for starting this thread!

You raise a good point about volume size. Should it be single batch size, double or triple?

What no maker has come up with yet is a conical fermentor based on a modular concept instead of a single piece of fabricated metal of a fixed volume.

Great points Feldon. Personally I would like a ~50L volume to be able to ferment either single or double batches under pressure.

I am inspired by the idea of modular design using sanitary fittings - it could even allow a 1, 2, 3x 25L cylindrical body design if someone was particularly ambitious.

I don't have time to list my needed/ideal attributes but will be back with this list soon

 

[Zorco]

Completely true that complexity adds to cost! May well be the criteria that decides against implementation!

Modular cylinder chalked up. Next specifications...

 

[fdsaasdf]

A quick google search reveals that 8" clamps are reasonably affordable at US$38 retail (https://www.brewershardware.com/8-Tri-Clover-Clamp-TC80CLAMP.html) so maybe a 12" or 15" isn't going to be unaffordable (however I'm not in the industry so this is speculation). Very happy to take advice from those who know much more than I.

1/4bbl and 1/2bbl kegs are 15.5" diameter for an indication of size.

A conceptual example:
Fabricate a 14.5" diameter cylinder with a 15" diameter stainless ferrule at each end; that is 10" high gives ~27L volume.

Attaching a 5" high cone with this 7.25" radius will result in ~4.5L extra volume that totals a 31.5L container (or 48.5L if two 'body' cylinders could be clamped on top of each other - let me dream!).

The top could be a clamped 15" plate or we could just source our own lids. Either way I'd prefer a simple top that can be opened for cleaning.

I wouldn't expect any fittings need to be attached to the body section.

For the conical section:
1x sanitary fitting as close as possible to the base of the cylinder as the bottom drain

1x sanitary fitting 2.5" vertically higher than the base (~2.25L deadspace)

1x fitting suitable for thermowell as close as practically possible to the top of this section.

4x external mounting points to attach legs

 

[Lager Bloke]

Hi all,toying with building a pressure fermenter and using adjustable cam action marine fasteners for the lid/top of vessel-was going to use say 4 or 5 of these around top +use silicon split hose on both edges(top and bottom of the join).The adjustable latches can be tweaked hopefully tight enough to seal properly without putting too much pressure on the silicon seal to have it stay put + not pop out/leak-maybe this can be done to join/add volume to the conical.May even have to put a flat face onto both joining edges and use a flat silicon seal sandwiched between each join.A good project Cosdog,very interested to see the outcomes,Rob.

 

[sixfignig]

I don't really have anything of value to add, but keen to follow progress.

 

[booargy]

Tri-clovers are expensive but well worth the coin. My wort boiler for starters only cost me about 1k

 

[fdsaasdf]

Tri-clovers are expensive but well worth the coin.

Nice photo. What diameter are your tri-clovers? How much were the clamps?

 

[booargy]

200mm or 8", clamp about $45, a spool is $200, reducer is $200, i have a 300mm ferrule and end cap and clamp which cost me about $500 from brewshardware.

 

[fdsaasdf]

200mm or 8", clamp about $45, a spool is $200, reducer is $200, i have a 300mm ferrule and end cap and clamp which cost me about $500 from brewshardware.

Thanks for the info - just to confirm was all the equipment from brewshardware? Or just the 300mm ferrules and end cap?

 

[booargy]

300mm came from brewershardware. spools and reducers from stilldragon

 

[Benn]

Compact, so it will fit inside your average fridge/chesty.
Adjustable/telescopic legs to cater for the above mentioned and provide adaptability/versatility re: compressor hump etc.
..main opening must be no wider than a domestic roll of glad wrap)

 

[Zorco]

Glad wrap. Check

 

[mr_wibble]

I like Feldon's idea of making it able to change size.

20 litre body-sections would be great. So you could buy the base-level 25-litre (20L base + 5L cone + lid), but then add another 20L body section to enable double-batch, triple-batch, etc.

I look at conicals now, and I see ones that are say 27 litres, and I think - "$800 and single batch only".
But if you could just change the size for another $200, well that's a different story.

Anyway, my idea is:

Instead of legs (or in addition to) it could simply sit in some kind of plastic holder, like the way an egg does in am egg-cup. Perhaps resting on the first cone-body join.
Something like a large-diameter plastic pipe, with holes cut to allow access to the lower port(s). This may be a cheaper option than welding on attachment points for legs.

-kt

 

[MHB]

https://www.toledometalspinning.com/products/product-catalog/seamless-hopper-cone-funnels
M

 

[klangers]

A couple of points to consider:

• If you're intending to pressure ferment, be aware that the fermenter may need to be certified as a pressure vessel (there is a certain tipping point with regards to vessel size and max operating pressure; AS 1210:2010). Does the fabricator have the necessary qualifications and licenses to do this?
  Who's going to sign off on this? Be aware that it is a criminal offence to fabricate and sell a pressure vessel that is not certified. I'm not saying don't do it, just go into this with both eyes open

[*]A vacuum breaker must be fitted. A few people will clean with hot water and then leave it in there, all sealed up. When the water cools, all the steam will condense and form a vacuum which will crush the vessel
[*]Is it worth considering jacketing? I personally won't be bothering with conicals until I build/buy a glycol reticulation system
[*]The internal surface roughness is critical. It needs to be polished otherwise your yeast won't slide down the cone and it will not be sanitary. From pre-caffeine memory Ra=0.2 is a pretty good target for polishing
[*]All welds must be TIG welded, with both sides being fully purged with argon. The welds will then need to be passivated, and depending on the rest of tank, the whole thing may need to be pickled with nitric acid (can use other acids). Your fabricator will know all this if he's worth your salt, but be aware that good stainless welds and related post-treatment take time. He may try to cut corners to save you cost
[*]Recommend 304 stainless. Yes, 316 is more chemically resistant but a shitload more expensive - 304 is best value for fermenters (if this was dairy I'd say 316)
[*]Recommend that the vessel/constituent components are size to fit onto common transport modes; eg consider a pallet size and height or you'll all end up paying more for delivery

Anyhow, I'm happy to take a look at the drawings if you want an engineer's (informal) opinion of the design.

 

[Zorco]

Mechanical / Process engineer?

 

[trhr]

Klanger makes a alot of valid points and I concur.

I'm a Builder with a specialised metal fabrication based business.
I could design, certify and fabricate this fermenter... The big problem doing this in Aus? Price!

Before we get too ahead of ourselves with design options and CADs, I would just hand sketch up a very basic fermenter carcass and get Harry to quote it on a small quantity, say 5 to 10.
You'll probably get quite the shock if it's been done right. He's got to make it worth his while too!
Be aware his price will not include pressure vessel verification and registration.

I love the idea of a custom scale-able pressurised fermenter and it's doable in Australia, but really only as a custom case by case for the guy who wants to shell out for it.
If this is the case I would think about doing it for the love for a few... but I'm time poor as it is, so it would be low on my priorities.
Maybe we put together just the specs/plans and certify them and put them out for the AHB community to fabricate/price as they wish? Perhaps an overseas bulk buy out of China?

I'm crossing my fingers that Harry lives on the smell of a oily rag and will do it for the love too though!!

 

[klangers]

Mechanical / Process engineer?

Aye sir

 

[Zorco]

I know Redman9.... This exploration and the rich supply of info is worth it almost on its own.

Harry has worked on jacketed gear - is that a pressure vessel? Can he certify? Don't know yet. Will ask.

One of the themes he mentioned a couple of times was using standard parts, like reducers for cone sections.

MHB: nod to you again, that's what will get us somewhere. Freight from the states or possibly
http://www.whitehorseindustries.com.au/capabilities.php

I can't say that pressure fermentation is on my spec. Recalling another thread, I intend to brew a lot more and improve on the basics first.

Harry is economical, nothing flash, happy as, helps his apprentice... But, you're right, this will cost money.

So what if I put a preliminary budget out there... A price to establish expectations.

$750-$1250

Booargy's boiler of majesty transformed into a fermenter might just about be right for me.

Hopefully this doesn't constrain creative input (as budgets do). Finding the components becomes the game.

 

[Liam_snorkel]

for me - I wouldn't spend coin on a stainless fermenter if I couldn't pressure ferment in it.

 

[Zorco]

Ok, will have to learn more. Cheers Liam

 

[booargy]

If you are going to have something fabricated you are better of getting what you want. It costs money to have things custom made and as cheap as he may be it is still going to take coin to buy materials and consumables. things like argon filler rod grinding discs they start to add up.

 

[Feldon]

Couple of thoughts on a jacketed (double walled) fermentor.

I’m no expert on thermodynamics, but I think at the homebrew scale only the central cylindrical unit would need to be jacketed to provide enough internal surface area to cool or warm a brew to the required fermentation temp (ie. no need to jacket the conical bottom section).

This jacketed central unit, made to the same dimensions as the standard central cylinder unit, could be an optional purchase for some buyers. It would be a great enhancement, but not everybody would want one, and to include it as standard would increase the cost of the basic model. This flexibilty is one of the benefits of the modular concept.

With the cone and lid being un-jacketed you would need to insulate these two units. I think you need to negate the influence of the outside ambient air temp as much as possible. On cold days you don’t want the heat of the brew leaking out into the colder outside air surrounding the cone and lid; and on warm days you don’t want the heat from the outside air getting into the brew via the cone and lid. You want the temp-controlled fluid circulating through the jacket to be in control of the ferment temp. So you insulate the non-jacketed units.

The bottom cone unit could easily be insulated with yoga mat material (just place cone upside down on bench, wrap until the mat overlaps, and cut in straight line through both layers of mat (put a piece of thin cardboard underneath so you don’t scratch the cone surface). You should end up with a perfect cone-shaped piece of mat that when the edges are glued together will form a snug fit over the conical base unit. Just cut out holes where needed for ports etc. The lid should be easy enough to insulate with yoga mat (or just chuck an old blanket over it).

As for pressure fermenting, how much pressure do brewers need? I know that some brewers who ferment this way also use the vessel’s pressure rating to force transfer the finished beer to kegs by using CO2 gas (rather than using pumps). Would this mean a higher pressure rating is needed than needed just for pressure fermenting.

Whatever, I don’t think it’s a huge pressure rating that is needed. Tri clamp fittings should be able to cope very well?

 

[mr_wibble]

https://www.toledometalspinning.com/products/product-catalog/seamless-hopper-cone-funnels
M

Wow ... so I can get an unpolished ~40 litre quasi-conical for $US205 (TMS16914).

I guess the devil is in the detail(ing).

 

[Feldon]

Another (cheaper?) option for joining the modular units together could be this type of clamp, instead of tri clamp.

 

[klangers]

I’m no expert on thermodynamics, but I think at the homebrew scale only the central cylindrical unit would need to be jacketed to provide enough internal surface area to cool or warm a brew to the required fermentation temp (ie. no need to jacket the conical bottom section).

This jacketed central unit, made to the same dimensions as the standard central cylinder unit, could be an optional purchase for some buyers. It would be a great enhancement, but not everybody would want one, and to include it as standard would increase the cost of the basic model. This flexibilty is one of the benefits of the modular concept.

Whatever, I don’t think it’s a huge pressure rating that is needed. Tri clamp fittings should be able to cope very well?

Yep you could only jacket the central part. Bear in mind this would limit the batch size flexibility. With no active cooling on the cone, you'd be limited on the minimum batch size.